JP3758536B2 - Echo canceller control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an echo canceller control method, and more particularly to an echo canceller control method in a subscriber transmission path in a wireless section.
[0002]
[Prior art]
Conventionally, a method for controlling an echo canceller apparatus using a signal frame format corresponding to TS16 (time slot) of a 2 Mbit / s transmission path and using 2 bits thereof is disclosed. In Japanese Patent Laid-Open No. 5-14984, a switching system that accommodates inter-station lines can share the control information path of various line processing devices, thereby simplifying the hardware configuration of the switching system, A technology that enables control of a line processing apparatus from an exchange system without depending on the installation location of the processing apparatus is disclosed. This technique is based on CCITT recommendation Q.10 when various line processing devices such as a digital line multiplexer, an echo canceller, and an A / μ converter on a line are controlled by an exchange system that accommodates an inter-station line. 50 Control signals are transferred using bits A to D on a specific time slot on the same transmission highway path conforming to ANNEX A, and the various line processing devices are controlled uniformly using the same transmission highway path. Is.
[0003]
As a means for determining the validity of data, Japanese Patent Application Laid-Open No. 10-200450 discloses a method for determining that data is valid after monitoring received data a predetermined number of times or more.
[0004]
Japanese Patent Application Laid-Open No. 11-205876 discloses a line capable of responding to a request that was impossible in the prior art by sending more types of control signals than in the prior art even when using the same number of bits as in the prior art. A technique regarding a control method of the processing apparatus is disclosed. This is because control information for controlling a plurality of line processing apparatuses such as an echo canceller apparatus, an A / m conversion apparatus, and a digital line multiplexing apparatus arranged on the inter-station line between exchanges is the inter-station line. Is transmitted by bits of a plurality of specific time slots of the digital multiple line constituting the message, and a message-based data link protocol is used as the control information.
[0005]
[Problems to be solved by the invention]
However, the prior art has the following problems.
[0006]
In the conventional method of controlling the echo canceller using 2 bits, when controlling the echo canceller, the TS16 equivalent must be used.
[0007]
The echo canceller has a technology that detects the tone and controls the echo canceller ON / OFF, but when the tone is transmitted from the subscriber terminal side, it is a compressed signal on the radio section, and the restored tone is surely Since there is no guarantee that it can be detected, there is a case where the echo canceller cannot be turned ON / OFF.
[0008]
In the technique disclosed in Japanese Patent Laid-Open No. 10-200450, since it cannot be determined that the data is valid unless the data is read a plurality of times, it takes time until one piece of data is taken out, the processing is complicated, and the processing capacity is lowered and the efficiency is reduced. There was a problem of being bad.
[0009]
The present invention has been made in view of such a problem, and the object of the present invention is to simply perform AND processing of the Enable bit and the control bit information using the empty bit of TS0 without using TS16. Thus, by obtaining effective information, a channel corresponding to TS16 is assigned as a call channel, and a technique relating to an echo canceller control method capable of efficient bit control with simple processing is provided.
[0010]
[Means for Solving the Problems]
The gist of the present invention according to claim 1 is that a subscriber transmission path between a switching system and a network terminating device for terminating a line unit includes a radio section, and the radio section compresses and transmits an audio signal, An echo canceller control method in a system for controlling an echo canceller of a radio control apparatus and an echo canceller apparatus connected to an exchange system, wherein the Sa bit which is an empty bit in TS0 is used for controlling the echo canceller, and TS0 is a multiframe take the configuration, the out of Sa bit, synchronization bit Sa8, using Sa6 and Sa5 echo canceller control bits, the Sa4 bits as Enable bits, the Sa6 and Sa5 set an echo canceller control information having the traffic channel minutes, those the Enable bit and Sa6 or Sa5 those of the frame of TS0 It retrieves the effective information and echo canceller control bits by AND processing consists in an echo canceller control method characterized by allocating a communication channel to channel using the signal frame format corresponding to TS16.
The gist of the present invention described in claim 2 is that the signal analysis unit of the network terminating device detects a tone transmitted from a subscriber terminal connected to a predetermined time slot after a call connection is established. Then, the first step of determining that the echo canceller is OFF (or ON) and transferring the control information to the signal on the radio section, and the Sa bit inserting unit of the radio control device includes the control information that has been transferred. A second step of setting the bit corresponding to the time slot in the Sa bit in the TS0 to OFF (or ON), and the echo canceller control unit of the echo canceller device includes the radio control device The Sa bit in the multi-frame transmitted from is analyzed, and the echo canceller corresponding to the time slot is turned off (or turned on). Resides in that it comprises of the steps to the echo canceller control method according to claim 1, wherein.
The gist of the present invention described in claim 3 is the ITU-T recommendation G. 3. The echo canceller control method according to claim 1, wherein Sa8, Sa6, Sa5, and Sa4 of the TS0 that are spare bits handled as reserve in 704 are used for control of the echo canceller.
The gist of the present invention described in claim 4 resides in a storage medium in which a program capable of executing the echo canceller control method according to any one of claims 1 to 3 is recorded.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0012]
FIG. 1 is a diagram showing a system for executing the echo canceller control method according to the present embodiment.
[0013]
As shown in FIG. 1, a system for executing an echo canceller control method according to the present embodiment includes an exchange system 1, an echo canceller apparatus 2 connected to the exchange system 1, a radio control apparatus 3, and a subscription. And the network termination device 4 that accommodates the user terminal 5.
[0014]
The echo canceller apparatus 2 includes an echo canceller control unit 21. The wireless control device 3 includes a Sa bit insertion unit 31. The network termination device 4 includes a signal analysis unit 41. The echo canceller apparatus 2 and the radio control apparatus 3 are connected by a 2 Mbit / s transmission path, and data communication is performed.
[0015]
Between the wireless control device 3 and the network termination device 4, a known CDMA system is adopted, and audio signals are compressed and transmitted.
[0016]
FIG. 2 is a diagram showing an example of the frame configuration of the line used in FIG.
[0017]
(A) of FIG. 2 is an example of 2048 Kbit / s frame data communicated between the echo canceller apparatus 2 and the radio network controller 3. The line used in FIG. 1 is divided into TS0 to 31 (time slots) and has a frame configuration of # 0 to # 15.
[0018]
FIG. 2B is a diagram showing the bit definition of TS0 in FIG.
[0019]
In the figure, the definitions of Sa4 to Sa8 (spare bits), C1 to 4 (CRC), A (remote alarm display), and E (spare bits for international use) are shown.
[0020]
3 to 5 show an information transmission method using the Sa bit defined on TS0 for executing the echo canceller control method according to the present embodiment.
[0021]
FIG. 3 is a diagram showing an example of the Sa bit defined on TS0 in FIG.
[0022]
ITU-T Recommendation G. In 704, Sa8, Sa6, Sa5, and Sa4 (spare bits), which are reserved, are defined in the format shown in FIG. 3, and echo canceller control information for the number of speech channels can be transmitted in a multiframe configuration.
[0023]
Here, as a reason not to use Sa7 (spare bit), it is considered that Sa7 is used when the V5.2 interface is used.
[0024]
The signal analysis unit 41 of the network terminating device 4 detects and analyzes the tone, judges echo canceller ON / OFF, converts the control information into a message, and transmits Sa for a predetermined time by the Sa bit insertion unit 31 of the wireless control device 3. And repeat items Nos. T0 to T16.
[0025]
The echo canceller control unit 21 of the echo canceller apparatus 2 reads and analyzes data within the Sa transmission time, and controls the echo canceller.
[0026]
Further, by using the data string shown in FIG. 3, the distinction between which TS (time slot) is ON / OFF is realized by the following method.
[0027]
The echo canceller control unit 21 identifies which item number the data being received is by reversing Sa8 from the time of receiving the item number (first item number) T0 among the item numbers T0 to T16.
[0028]
The determination of the item number T0 can be realized when Sa8 = 0 continues twice and Sa5 changes from “1” to “0”. If the next data cannot be transmitted with an item number (for example, item number T2) other than the item number (last item number) T16 due to line abnormality, Sa8 = 0 continues twice. Therefore, it can be determined that the communication is abnormal. The reason why Sa6 = 1 of the item number T0 is set to be clear by the determination of the item number T0. After determining the item number T0 in this way, the item number can be identified by reversing Sa8, so that the TS can be determined.
[0029]
FIG. 4 is a diagram showing an example of a time chart of the Sa bit information transmission method in the echo canceller control method according to the present embodiment.
[0030]
As shown in FIG. 4, Sa8 is a synchronization bit, Sa6 and Sa5 are echo canceller control bits (data bits), and Sa4 is an enable bit. Sa8, Sa6, and Sa5 are enabled when Sa4 = 0, and Sa4 = 1 when changing the echo canceller control bit.
[0031]
FIG. 5 is a diagram showing an example of a sequence in the echo canceller control method according to the present embodiment.
[0032]
With reference to FIG. 5, a method of controlling the echo canceller corresponding to TS1 will be described assuming that the subscriber connected to TS1 is a modem communication subscriber.
[0033]
A tone is transmitted from the modem of the subscriber terminal 5 when the data communication is started after the subscriber terminal 5 of the subscriber is connected. The signal analyzing unit 41 of the network terminating device 4 detects a tone, determines that the echo canceller is OFF, and converts the control information into a message (step S71).
[0034]
The Sa-bit insertion unit 31 of the radio network controller 3 sets the corresponding message signal to OFF (TS6 = 0 in the frame of the item number T1) (step S72).
[0035]
The echo canceller control unit 21 of the echo canceller apparatus 2 analyzes the Sa bit in the multiframe transmitted from the radio control apparatus 3, and turns off the echo canceller corresponding to TS1 (step S73).
[0036]
As described above, the echo canceller apparatus 2 corresponding to the modem communication subscriber of TS1 can be operated OFF.
[0037]
Conversely, when it is desired to turn on the echo canceller corresponding to TS1, the Sa bit inserting unit 31 sets Sa6 = 1 in the frame of the item number T1.
[0038]
Similarly, the case of controlling the echo canceller apparatus 2 corresponding to another TS (time slot) can be realized by setting a value to the bit of the frame of TS0.
[0039]
As described above, the present embodiment includes a wireless section in the subscriber transmission path between the switching system 1 in FIG. 1 and the network terminating device 4 that terminates in units of lines, and the wireless section compresses and transmits voice signals. In addition, the present invention relates to a method for controlling an echo canceller apparatus in a system in which the radio controller apparatus 3 and the echo canceller apparatus 2 are connected by a transmission line and require control of the echo canceller apparatus in addition to line processing.
[0040]
In the wireless section, a voice signal is compressed and transmitted, and when a tone is transmitted from the subscriber terminal side, there is no guarantee that the restored tone can be reliably detected. The echo canceller apparatus is turned on / off, converted into a message, and a control signal is transmitted using the bit of TS0 on the transmission path to control the echo canceller apparatus.
[0041]
Since the echo canceller control method according to the embodiment is configured as described above, the following effects can be obtained.
[0042]
As a means for judging the validity of the data, a method of judging that the data is valid after reading the data a plurality of times is common, but in this embodiment, the ON / OFF of the echo canceller apparatus 2 is controlled. In this case, by using the Enable bit of FIG. 4, it becomes possible to grasp at the time of data change, and the Enable bit and the data can be ANDed and the valid data can be taken out once without reading the data multiple times. .
[0043]
This embodiment can also be applied to a V5.2 interface using TS16.
[0044]
Any bits of Sa4, Sa5, Sa6, and Sa8, which are reserved for TS0 and used for echo canceller control, may be used as long as they are not used for other purposes. (In the V5.2 interface, Sa7 is used for other purposes.)
Furthermore, “0/1” designation of bits may be reversed, and data may be assigned to any bit of Sa8, Sa6, Sa5, and Sa4. The wireless section may be other than the CDMA system. The transmission path may have a transmission rate other than 2 Mbit / s. The number of multi-frames of TS0 conforms to the number of call channels.
[0045]
In the present embodiment, the present invention is not limited to this, and can be applied to an echo canceller control method suitable for applying the present invention.
[0046]
In addition, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a suitable number, position, shape, and the like in practicing the present invention.
[0047]
In each figure, the same numerals are given to the same component.
[0048]
【The invention's effect】
Since this invention is comprised as mentioned above, there exists an effect hung up below.
[0049]
In a system that requires control of the echo canceller device, the TS16 equivalent can be used as a call channel by transmitting the echo canceller control signal using the bit of TS0 on the transmission line. Many can be assigned.
[0050]
In addition, when the ON / OFF of the echo canceller is controlled, by using the Enable bit, it is possible to extract valid information at a time just by taking the AND of the Enable bit and the control bit information. Bit control processing can be performed well.
[Brief description of the drawings]
FIG. 1 is a diagram showing a system for executing an echo canceller control method according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of a frame configuration of a line used in FIG.
FIG. 3 is a diagram illustrating an example of a Sa bit defined on TS0 in FIG. 2;
FIG. 4 is a diagram showing an example of a time chart of a Sa bit information transmission method in an echo canceller control method according to an embodiment of the present invention.
FIG. 5 is a diagram showing an example of a sequence in an echo canceller control method according to an embodiment of the present invention.
[Explanation of symbols]
A Remote alarm display C1-4 CRC
E Spare bits for international use Sa4 to Sa8 Spare bits TS0 to 31 Time slots T0 to T16 No. 1 Switching system 2 Echo canceller device 3 Radio control device 4 Network termination device 5 Subscriber terminal 21 Echo canceller control unit 31 Sa bit insertion unit 41 Signal Analysis Unit

Claims (4)

A subscriber transmission path between a switching system and a network terminating device that performs line-by-line termination includes a wireless section, and the wireless section compresses and transmits a voice signal. The wireless control apparatus connected to the switching system and an echo An echo canceller control method in a system for controlling an echo canceller of a canceller device,
The Sa bit, which is an empty bit in TS0, is used for echo canceller control. TS0 takes a multi-frame configuration, and among the Sa bits, Sa8 is a synchronization bit, Sa6 and Sa5 are echo canceller control bits, and Sa4 bit is an enable bit. as used, the Sa6 and Sa5 set an echo canceller control information having the traffic channel minutes, the effective information to aND processing and those the echo canceller control bits and those the enable bit of the frame of TS0 Sa6 or Sa5 An echo canceller control method, comprising: extracting and assigning a channel using a signal frame format corresponding to TS16 as a communication channel. The signal analysis unit of the network terminating device detects a tone transmitted from the subscriber terminal after the subscriber terminal connected to the predetermined time slot is connected to the call, and cancels echo canceller OFF (or ON). A first step of determining and transferring control information to a signal on the radio section;
The Sa bit insertion unit of the radio network controller sets the bit corresponding to the time slot in the Sa bit in the TS0 to the control information that has been transferred is set to OFF (or ON). Steps,
The echo canceller control unit of the echo canceller apparatus analyzes the Sa bit in the multiframe transmitted from the radio control apparatus, and sets the echo canceller corresponding to the time slot to OFF (or ON). The echo canceller control method according to claim 1, further comprising:   ITU-T Recommendation G. 3. The echo canceller control method according to claim 1, wherein Sa8, Sa6, Sa5, and Sa4 of the TS0 that are spare bits handled as reserve in 704 are used for control of the echo canceller.   A storage medium in which a program capable of executing the echo canceller control method according to claim 1 is recorded.

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